Improving animal welfare of turkeys at slaughter

This project aims to improve animal welfare of turkeys at slaughter by using an innovative nitrogen gas stunning method. By replacing traditional electrical stunning methods, this approach eliminates the need for shackling birds before stunning, significantly reducing stress and pain.

Objectives

The project will compare electrical head-only stunning with an innovative controlled atmosphere stunning method that uses a high concentration nitrogen gas delivered in high-expansion foam. The comparison will be in terms of animal welfare, behavior, physiological parameters, slaughter conditions and meat quality.

Background:

The welfare of animals during slaughter is a key concern in modern agriculture. In Sweden, electrical stunning is commonly used for turkeys, but this method involves shackling conscious birds, leading to stress and potential injuries. Gas stunning, while promising, has its drawbacks, as birds can experience stress when exposed to carbon dioxide before losing consciousness. Gas stunning with nitrogen gas, which is less adversive than carbon dioxide, has been difficult to achieve since it is relatively the same density as air which makes it difficult to produce and maintain an atmospher with less than 2% oxygen as needed for anoxic stunning. This project explores an innovative gas stunning methods that delivers the nitrogen gas (N2) in a high-expansion foam which can quickly displace the existing air from a container and create a pure nitrogen gas anoxic atmosphere perfect for stunning the birds quickly and painlessly without the need for shackling or pre-handling at all, they can be stunned in their transport crate.

Experimental approach:

The project had two experiments. 1) Compare exposure of turkeys to air-filled foam and nitrogen-filled foam to dissern what behavioral reactions were due to the foam and which were due to the nitrogen gas stunning. Observations included behavior, time to loss of posture (i.e., loss of consciousness), convulsion intensity and duration and stun quality. Additional observations included foam fill time, oxygen concentration and temperature levels. 2) Compare turkeys stunned using traditional electrical head-only stunning and using the N2 foam stunning under slaughter conditions. . Observations included stress-related behaviors, welfare indicators, and post-slaughter parameters and meat quality.

Why it matters:

Improving animal welfare at slaughter is a growing concern for consumers, producers, and retailers alike. By developing a method that reduces stress and improves welfare, this project supports the Swedish poultry industry in maintaining high ethical standards while also ensuring product quality. The project aligns with the One Welfare Concept, connecting animal welfare with human well-being and environmental sustainability.

Ethical approval:

The research experiment received ethical approval by Gothenburg's Animal Experimentation Ethics Committee Idnr 003910.

Previous studies:

RISE and SLU has previously tested this nitrogen gas foam method for stunning small pigs which showed positive results, see publications:

Lindahl, C., Sindhøj, E., Brattlund Hellgren, R., Berg, C., Wallenbeck, A., 2020. Responses of pigs to stunning with nitrogen filled high-expansion foam. Animals, 10(12), 2210; https://doi.org/10.3390/ani10122210.